JP2986571B2 - Mechanical scanning ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical scanning ultrasonic probe used for medical ultrasonic diagnostic equipment and the like.

[0002]

2. Description of the Related Art Generally, a power transmission mechanism of a mechanical scanning type ultrasonic probe is provided with teeth because it is necessary to reliably transmit a driving force of a driving means. Hereinafter, a conventional mechanical scanning ultrasonic probe will be described with reference to FIG.

In FIG. 4, reference numeral 1 denotes a motor with an encoder fixed to a frame 5, and 2 denotes an ultrasonic vibrator for transmitting and receiving ultrasonic waves. A housing 4 is filled with an ultrasonic wave propagating medium 9 such as butanediol. It is attached to the frame 5 so as to be rotatable. 13A and 13B are a drive side gear and a driven side gear, respectively, and 13C and 13D are a toothed pulley and a toothed belt, respectively. By combining these, the driving force of the motor with the encoder is transmitted and the ultrasonic vibrator is rotated. . 6 is an oil seal, 8
Is a cable for transmitting and receiving various signals to and from the motor with encoder 1 and the ultrasonic probe 2.

In the conventional example described above , the toothed pulley 13
C and the toothed belt 13D have 36 teeth and 78 teeth, respectively. At this time, the toothed pulley 13C and the toothed belt 1
Looking at a set of teeth that mesh with each other between 3D,
Since the least common multiple of 6 and 78 is 468, if the toothed pulley 13C rotates 13 times and the toothed belt 13D rotates 6 times, the same teeth once meshed will mesh again .

[0005]

However, in the above-described conventional mechanical scanning ultrasonic probe, if the tooth shapes of the toothed pulley 13C and the toothed belt 13D are all the same, there is no transmission error of the rotation angle, Pulley 13C and toothed belt 13
Due to the processing accuracy of D, the eccentricity of the rotation center of the toothed pulley 13C and the eccentricity of the tooth surface, etc., in FIG. 4, a large and slow swing appears on the display image in which the ultrasonic transducer 2 makes one cycle with 13 rotations. A long-period swing that can be visually confirmed during ultrasonic diagnosis.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an excellent mechanical scanning ultrasonic probe which is free from long-period image fluctuation on an ultrasonic diagnostic image generated by the influence of a power transmission mechanism. It is intended for.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rotary drive means, an ultrasonic vibrator which is rotatably supported and transmits and receives ultrasonic waves, and an ultrasonic transducer between all the meshed toothed members. Each tooth ratio is 1: N (N = integer)
And transmission means for transmitting the driving force of the rotation driving means to the ultrasonic vibrator, the transmission means comprising two or more sets of toothed members.

[0008]

According to the present invention, the above configuration eliminates long-period image fluctuations on an ultrasonic diagnostic image generated by the influence of a power transmission mechanism in a mechanical scanning ultrasonic probe.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a mechanical scanning type ultrasonic probe using a toothed belt transmission mechanism according to a first embodiment of the present invention. Here, the same components as those in the conventional example are denoted by the same reference numerals. In FIG. 1, a toothed pulley 3C and a toothed belt 3D are used as a mechanism for reliably transmitting the power of the motor with encoder 1 to the ultrasonic vibrator 2. At this time, the ratio of the number of teeth between the toothed pulley 3C and the toothed belt 3D is set to 1: N (N = integer). When the toothed pulley 3C makes N rotations, the toothed belt 3D makes one rotation, and the original teeth mesh with each other. Then
In proportion to this, one cycle of the swing of the display image is determined by the ultrasonic transducer 2
N rotations. The shorter the oscillation period of the display image transmission mechanism is, the smaller the sensory sensation that cannot be confirmed by the monitor or the visual tracking ability.
The smaller the better.

FIG. 2 is a sectional view of a mechanical scanning ultrasonic probe using a gear transmission mechanism according to a second embodiment of the present invention. In FIG. 2, when the ratio of the number of teeth between the driving side gear 3A and the driven side gear 3B is 1: N (N = integer), as described with reference to FIG. One cycle is performed by N rotations, and the smaller the tooth number ratio N is, the more it is not possible to confirm the function. Further, when the ratio of the number of teeth is 1: 1, the correlation between the driving side gear 3A and the driven side gear 3B is easily obtained, so that the combination having the same eccentricity is used. And the largest part of the driven gear 3B are engaged with each other, so that the deflection of the ultrasonic transducer 2 caused by the eccentricity of the driving gear 3A and the driven gear 3B is reduced,
The fluctuation on the display image is further reduced.

FIG. 3 is a sectional view of a mechanical scanning type ultrasonic probe using a transmission mechanism using gears and a toothed belt according to a third embodiment of the present invention. In FIG. 3, the ratio of the number of teeth between the driving gear 3A and the driven gear 3B, the toothed pulley 3C and the toothed belt 3D is 1: N (N = integer). In this case, the fluctuation of the displayed image corresponds to the periodicity of the rotational position error of the ultrasonic transducer 2 when a value obtained by multiplying the tooth ratio N of the driven gear 3B by the tooth ratio N of the toothed belt 3D.

[0013]

According to the present invention, as is apparent from the above embodiment, in a mechanical scanning type ultrasonic probe, the driving force of the rotary driving means is transmitted to the ultrasonic transducer via a plurality of toothed members. among the transmission means, any number of teeth ratio between toothed member meshing with each other, each 1: with N (N = integer),
Parts of power transmission mechanism such as gears, toothed pulleys, toothed belts, etc., when the ultrasonic transducer rotationally scans, because the period until the same tooth meshes again between toothed members meshing with each other becomes shorter. There is an effect that long-period image fluctuation on the ultrasonic diagnostic image generated due to the accuracy and the assembly accuracy can be eliminated.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a mechanical scanning ultrasonic probe according to a first embodiment of the present invention.

2A is a front sectional view of a mechanical scanning ultrasonic probe according to a second embodiment of the present invention, and FIG.

FIG. 3 is a front sectional view of a mechanical scanning ultrasonic probe according to a third embodiment of the present invention.

FIG. 4 is a front sectional view of a conventional mechanical scanning ultrasonic probe.

[Explanation of symbols]

 Reference Signs List 1 motor with encoder 2 ultrasonic transducer 4 housing 5 frame 6 oil seal 7 case 8 cable

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kiyoshi Fujii 4-1-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. (56) References JP-A-60-114240 (JP, A) JP-A-2-286144 (JP, A) JP-A-2-208071 (JP, A) JP-A-62-264979 (JP, A)

Claims (1)

(57) [Claims] 1. A rotary drive unit, and the ultrasonic transducer for transmitting and receiving ultrasonic waves is rotatably supported, number of teeth ratio between all intermeshing toothed member each 1: is N (N = integer) Transmission means for transmitting the driving force of the rotary drive means to the ultrasonic vibrator, the transmission means comprising two or more sets of toothed members, and the same teeth between the toothed members meshing with each other in the transmission means A mechanical scanning ultrasonic probe characterized in that a period until meshing is shortened to eliminate a long-period image fluctuation on an ultrasonic diagnostic image obtained by rotational scanning of the ultrasonic transducer.